Making Physical Inferences to Enhance Wireless Security

ABSTRACT

Securing wireless communication remains challenging in dynamic environments due to the shared nature of wireless medium and lacking of fixed key management infrastructures. Generating secret keys using physical layer information thus becomes an attractive alternative to complement traditional cryptographic-based methods. Although recent work has demonstrated that Received Signal Strength (RSS) based secret key extraction is practical, existing RSS-based key generation techniques can only obtain coarse-grained information of the radio channel and are hence largely limited in the rate they generate secret bits. In this project, we show that exploiting the channel response from multiple Orthogonal Frequency-Division Multiplexing (OFDM) subcarriers can provide fine-grained channel information and achieve higher bit generation rate for both static and mobile cases in real-world scenarios. We further develop a Channel Gain Complement (CGC) assisted secret key extraction scheme to cope with channel non-reciprocity encountered in practice. Our extensive experiments using WiFi networks in both indoor as well as outdoor environments demonstrate the feasibility of the practical application of utilizing Channel State Information to perform secret key extraction. The experimental results also show that our proposed approach is resilient to malicious attacks identified to be harmful to RSS-based techniques including predictable channel attack and stalking attack. Thus, our preliminary work shows that it is practical to enhance wireless security by making inferences using unique physical properties.

Yingying (Jennifer) Chen is an Associate Professor in the Department of Electrical and Computer Engineering at Stevens Institute of Technology. Her research interests include cyber security and privacy, wireless and sensor networks, mobile social networks and pervasive computing. She received her Ph.D. degree in Computer Science from Rutgers University. Prior to joining Stevens Institute of Technology, she was with Alcatel-Lucent at Holmdel & Murray Hill, New Jersey. She has co-authored the book Securing Emerging Wireless Systems Springer 2009 and published over 70 journal articles and referred conference papers. She is the director of Data Analysis and Information Security (DAISY) Lab at Stevens. She is the recipient of the NSF CAREER Award 2010 and Google Research Award 2010. She received Stevens Board of Trustees Award for Scholarly Excellence in 2010. She is also the recipient of the Best Paper Awards from ACM International Conference on Mobile Computing and Networking (MobiCom) 2011 and International Conference on Wireless On-demand Network Systems and Services (WONS) 2009, as well as the Best Technological Innovation Award from the International TinyOS Technology Exchange 2006. She also received the IEEE Outstanding Contribution Award from IEEE New Jersey Coast Section each year 2005-2009. She received New Jersey Inventors Hall of Fame Innovators Award 2012. Her research has been reported in numerous media outlets including the Wall Street Journal, MIT Technology Review, Inside Science, NPR, and CNET.